The present invention relates to a synthetic sport surface, particularly a water-permeable, resilient surface having a tufted, synthetic grass-like fiber pile.
U.S. Pat. No. 3,869,421 and U.S. Pat. No. 3,846,364 disclose resilient surfaces made, for example, with particles of rubber and a polyurethane binder, and other components. The '421 patent discloses a non-porous as well as a porous, resilient surface, and the '364 patent discloses a generally porous, resilient surface. Both references disclose, for example at column 5, line 26 of the '421 patent and column 5, line 25 of the '364 patent, that a grass-type carpet may be combined with the porous, resilient surface to obtain a playing field with the advantage of porosity and maintenance of a dry playing field. However, no method is given for obtaining a water-permeable, tufted, grass-type carpet.
Generally, tufted yarn-type carpets are obtained by tufting the fibers or yarn into a backing and then applying a latex or polyurethane to the backing to hold the tufts in place. Without the latex or polyurethane or the like, the tufts do not have stability and can relatively easily be dislodged from the fabric backing. The latex or polyurethane backing is not water permeable.
In the past, water-permeable playing surfaces have, however, been made by knitting (as opposed to tufting) the pile of the grass-like surface onto a backing and attaching a perforated, resilient, mat-like surface (for example, perforated foam rubber) to the backing of the knitted, grass-like surface. An adhesive is typically used to attach the rubber or foam mat to the grass-like surface, but the adhesive is not applied continuously on the backing as such would destroy the water permeability. In this regard, see for example, U.S. Pat. No. 3,332,828 entitled "Monofilament Ribbon Pile Product", at column 7, lines 54-56.
These knitted-type grass surfaces are not readily produced with heavy denier yarn.
Decorative carpet has been formed in the past by others by fusing or thermobonding tufted polypropylene to a membrane which membrane is formed, for example, from glass fibers.